Mercedes 1017 trailer lights output question

[Poccur]

I am helping out some friends with the Chilean military and they have up-armoured HMMWVs and Mercedes 1017 vehicles. My trailers have the standard NATO 12 pin connector on and run fine on the HMMWVs...When I put them on the Mercedes the running lights work, the turn signals work but no brake lights. If I read from the back of the connector on the 1017 when they hit the air-brakes pin N goes to 24V...this does not fit with the normal pin-out for this NATO standard connector.
Has anyone come across a similar variation in the pin-outs for the trailer lights on a 1017? Does anyone have a circuit diagram they can share please?

Only solution I can think is to make an adapter cable so the pin N energizes pins B and J on the trailer, leave the other pins as they are...then the 1017 works with the trailer and they can take off the adapter cable for use with the HMMWV.

Thanks in advance for your input.
Regards
Poccur

 

[Poccur]

Have an update. Looked at the Merc 1017 and the Uni Mog today...both of them use B and J as turn signals and only pin N for brakes.
I checked pin M but nothing....

I am building and Xclusive-OR gate network with relays and diodes to combine the turn signals and brakes from the Merc for use with a HMMWV trailer..

 

[Poccur]

OK...here is what i have so far. Plan is to add the adapter cable between the existing trailer light harness and the Mercedes vehicle output.